The word desinence – pronounced with the stress on the first syllable, IPA: / 'dɛ sɪ nəns/ - is a technical term sometimes used by grammarians to refer to the ending or termination of a word, especially an inflectional ending, i.e., an ending in contrast to the stem or root to which different endings are added in the declension of a noun or the conjugation of a verb. For example, in the Latin noun mensam, the accusative case of the noun mensa, ‘table’, the desinence is –am, which is added to the stem mens-; similarly, in the Latin amaverunt, ‘they have loved’, -erunt is a desinence added to the perfect stem (amav-) of the verb amare, ‘to love’.
The word desinence is not often used in the study of English grammar – at least partly because English is not a highly inflected language – and the word has no entry in e.g., The Oxford Dictionary of English Grammar (Bas Aarts, Sylvia Chalker, & Edmund Weiner, eds. 2nd edition, 2014). It is more commonly found in grammatical studies of more highly inflected languages such as Latin, Greek, and Russian.